Requirements

Standard library has support for SSL transport. However, it is impossible to use
it with certificates provided as a string. We store certificates in database,
because we handle different apps on many Celery worker machines. A dirty
solution would be to create temporary files, but it is insecure and slow. So,
we have decided to use a better OpenSSL wrapper and pyOpenSSL was the
easiest to handle. pyOpenSSL is loaded on demand by standard networking
back-end. If you use your own back-end, based on some other SSL implementation,
then you don’t have to install pyOpenSSL.

Alternatives

Support certificates from strings. We do not distribute certificate files
on worker machines, they fetch it from the database when needed. This
approach simplifies deployment, upgrades and maintenance.

Keep connections persistent. An SSL handshaking round is slow. Once
connection is established, it should remain open for at least few minutes,
waiting for the next batch.

Support enhanced format. Apple developers have designed a notoriously bad
push protocol. They have upgraded it to enhanced version, which makes it
possible to detect which messages in the batch have failed.

Clean pythonic API. No need for lots of classes, long lists of exceptions etc.

Changelog

v0.2

Networking layer became pluggable, making gevent based implementations
possible. Everything is refactored, such that IO, multi-threading and SSL
are now loaded and used on demand, allowing you to cleanly override any
part of the client. The API is largely backward compatible. IO related
configuration is moved to transport layer and exception handling is a bit
more verbose. The client is using standard logging to send fine grained
debug messages.

v0.1

First simple implementation, hardwired with raw sockets and pyOpenSSL.
It does not work in gevent or any other green environment.

Support

APNs client was created by Sardar Yumatov,
contact me if you find any bugs or need help. Contact Getlogic if you need a full-featured push notification service
for all popular platforms. You can view outstanding issues on the APNs
Bitbucket page.